FAQ

Where do fine particles come from?

Every year in France, air pollution and fine particles cause 40,000 premature deaths. If we’re going to reduce that impact, we need to understand more about them. But behind the generic term “fine particles” lurks a variety of meanings. Fine particles can take different sizes and shapes, can be made up of different things, and can come from different sources. It’s time to take a closer look.
no-image

Natural and human-made sources

  • Some fine particles come from natural sources and are difficult to prevent. They might be emitted during volcanic eruptions, desert sandstorms, forest fires or earthquakes. They can also be produced in sea spray and wind-eroded soil. Volatile organic compounds sometimes come from certain plant species and form fine particles in a chemical reaction with the air.

 

  • But most fine particles are generated by humans. The top two sources are home heating in residential areas (wood-burning fires especially) and road transport. These activities are therefore respectively responsible for half and a quarter of fine particle emissions in Ile-de-France. Industry, construction,agriculture, forestry (spreading, tillage) and non-road transport also actively contribute to fine particle air pollution.

Primary particles, secondary particles and resuspended particles

Combustion, friction, chemical reactions: fine particles are generated for a variety of reasons.

  • They can be emitted directly into the atmosphere due to combustion or friction, when a material is gradually broken down. These are known as “primary particles”. Primary particles are generated by forms of transport, home heating systems, and industrial or agricultural activities. In the case of petrol or diesel vehicles, fine particles come both from the exhaust gases produced by fuel combustion and from abrasion – friction – between brakes and tyres.
  • But fine particles can also be created as a result of chemical reactions with atmospheric gases such as sulphur dioxide (SO2), nitrogen oxides (NOx) and volatile organic compounds (VOCs), known collectively as “secondary particles”.
  • Once they have fallen to the ground, these fine particles have not yet finished their journey. They can be resuspended in the atmosphere. For example, fine particles on roads are lifted into the air again when a car passes.

 

Even though fine particles originate from various sources and phenomena, they are all dangerous to health and disruptive to ecosystems. Underestimated by lawmakers, this invisible threat nevertheless generates far too many medical issues and exposes local residents to dangerous and sometimes fatal diseases. A connection has been found with a number of respiratory (pharyngitis, tracheitis, bronchitis, asthma, etc.), cardiovascular (arrhythmia, heart attacks, thrombosis, etc.), and neurodegenerative diseases (Alzheimer’s, Parkinson’s) and an increased risk of cancer (particularly of the lungs). It is high time to eliminate out this evil.

Discover more questions

There are 1.4 billion vehicles in circulation on the world’s roads. From the factory to the scrap yard, these vehicles require raw materials to be extracted from the earth, then emit CO2 and fine particles, which cause damage to our health and our planet. But what’s the solution? Use your car as little as possible, and opt for greener transport solutions: walking, cycling or public transport. But France is a very car-centric country. The best idea is to reduce – as best you can – how much pollution your car generates.
As we inhale 15,000 litres of air every day, we are continually exposed to air pollution, especially in large cities. These gases and fine particles are not only harmful to our health, but they also damage the environment and ecosystems and accelerate climate change. Where does air pollution come from? Although pollutants may be of natural origin: pollens, forest fires, sand mists, soil erosion, and volcanic eruptions generate pollution over which we have very little control, human activity is the main source of air pollution. That is evidenced by the sharp decline in air quality from the 19th century, with the development of industry and road traffic.
Air pollution exposure causes 40,000 deaths each year in France. How? Road transport comes top on the list of pollutant sources, neck and neck with the residential sector (home heating especially). Pollution is generated by vehicle traffic during chemical and physical reactions: